Windows 10 HDR Default Setting?

[CHiLL]

I have my PC (1080 Ti) hooked up to my TV (LG OLED C8) via a HDMI 4:4:4 certified cable in an effort to play games in HDR (that support it). I understand that the 1080 Ti is limited to HDMI 2.0b and can only support 10-bit 4:2:2 or 8-bit 4:4:4...however I've ran into issues.

 

If I set Windows to HDR and leave the Nvidia control panel to "Use default colour settings", the TV picks up HDR mode fine. However I don't know what it's been set to in terms of 8-bit/10-bit and 4:2:2/4:4:4. When the Nvidia control panel is set the default, the grayed out override settings change to 8-bit RGB. I don't know if that means anything. The Colour Management Control Panel applet doesn't have any profiles assigned and the TV shows as a Generic PnP Monitor. The Advanced tab has the all the settings as default and the device profile selected is "System default (sRGB IEC61966-2.1)

 

If I override the settings in the Nvidia control panel and specify 10-bit 4:2:2, everything goes goes very pink. If I set it as 8-bit 4:4:4, it appears to be fine. Though I'd prefer to use 10-bit if possible.

 

So if I leave it as default Windows settings - what's it being set to? Windows isn't very good at telling me that sort of thing. (That I can find anyway)